INTERIOR MAGNET MACHINE DESIGN WITH LOW CORE LOSSES

1 . A method of estimating core loss in an electric motor using a finite element analysis (FEA) simulation, comprising the acts of:

receiving a FEA model to represent at least one portion of an electric motor in a computer system, the computer system comprising a user interface and a processing circuit configured for FEA simulations, the electric motor comprising at least one rotor capable of rotation about a rotational axis and a stator having at least one pole pair disposed radially about the rotational axis of the rotor;

placing, with the user interface, at least one flux analysis coil at a first location around at least one portion of the rotor or stator of the electric motor in the FEA model, each flux analysis coil comprising a single wire loop;

calculating a time-domain flux density B of the at least one flux analysis coil as a function of time;

converting the calculated flux density function to a frequency-domain spectrum;

receiving material core loss parameters for at least some frequencies indicated by the frequency-domain spectrum; and

determining a core loss of the at least one portion of the electric motor by a weighted combination of the received material core loss parameters according to relative magnitudes of peaks in the frequency-domain spectrum.

2 . The method of claim 1 , further comprising the act of modifying, adjusting, or redesigning a FEA model based on the estimated core loss so as to minimize core loss.

3 . The method of claim 2 , further comprising manufacturing a physical electric motor based on the modified, adjusted, or redesigned FEA model.

4 . The method of claim 1 , wherein the at least one portion of the electric motor comprises at least one portion of the at least one rotor and at least one portion of the stator.

5 . The method of claim 1 , further comprising executing a time-stepped FEA simulation of the FEA model.

6 . The method of claim 1 , further comprising receiving an output from the processing circuit configured for FEA simulations, the output comprising a flux linkage or the time-domain flux density of the at least one flux analysis coil as a function of time.

7 . The method of claim 1 , wherein converting the calculated flux density function to a frequency-domain spectrum comprises computing a discrete Fourier transform (DFT) of the time-domain flux density function.

8 . The method of claim 1 , wherein the material core loss parameters comprise B-P curves.

9 . An apparatus for estimating core loss in an electric motor using a finite element analysis (FEA) simulation, the apparatus comprising:

means for receiving a FEA model to represent at least one portion of an electric motor in a computer system, the computer system comprising a user interface and a processing circuit configured for FEA simulations, the electric motor comprising at least one rotor capable of rotation about a rotational axis and a stator having at least one pole pair disposed radially about the rotational axis of the rotor;

means for placing at least one flux analysis coil at a first location within the rotor or stator of the electric motor in the FEA model, each flux analysis coil comprising a single wire loop;

means for calculating a time-domain flux density B of the at least one flux analysis coil as a function of time;

means for converting the calculated flux density function to a frequency-domain spectrum;

means for receiving material core loss parameters for at least some frequencies indicated by the frequency-domain spectrum; and

means for determining a core loss of the at least one portion of the electric motor by a weighted combination of the received material core loss parameters according to relative magnitudes of peaks in the frequency-domain spectrum.

10 . The apparatus of claim 9 , wherein the at least one portion of the electric motor comprises at least one portion of the at least one rotor and at least one portion of the stator.

11 . The apparatus of claim 9 , further comprising means for executing a time-stepped FEA simulation of the FEA model.

12 . The apparatus of claim 9 , further comprising means for receiving an output from the processing circuit configured for FEA simulations, the output comprising a flux linkage or the time-domain flux density of the at least one flux analysis coil as a function of time.

13 . The apparatus of claim 9 , wherein converting the calculated flux density function to the frequency-domain spectrum comprises computing a discrete Fourier transform (DFT) of the time-domain flux density function.

14 . The apparatus of claim 9 , wherein the material core loss parameters comprise B-P curves.

15 . A computer program product for processing data for a program configured to estimate core loss in an electric motor using a finite element analysis (FEA) simulation, the computer program product comprising:

a non-transitory computer-readable medium having stored thereon code for causing processing circuitry to:

enable a user to receive a FEA model to represent at least one portion of an electric motor in a computer system, the computer system comprising a user interface and a processing circuit configured for FEA simulations, the electric motor comprising at least one rotor capable of rotation about a rotational axis and a stator having at least one pole pair disposed radially about the rotational axis of the rotor;

enable placement, with the user interface, of at least one flux analysis coil at a first location within the rotor or stator of the motor in the FEA model, each flux analysis coil comprising a single wire loop;

calculate a time-domain flux density B of the at least one flux analysis coil as a function of time;

convert the calculated flux density function to a frequency-domain spectrum;

receive material core loss parameters for at least some frequencies indicated by the frequency-domain spectrum; and

determine a core loss of the at least one portion of the electric motor by a weighted combination of the received material core loss parameters according to relative magnitudes of peaks in the frequency-domain spectrum.

16 . The computer program product of claim 15 , wherein the at least one portion of the electric motor comprises at least one portion of the at least one rotor and at least one portion of the stator.

17 . The computer program product of claim 15 , wherein the code stored on the non-transitory computer-readable medium further causes processing circuitry to execute a time-stepped FEA simulation of the FEA model.

18 . The computer program product of claim 15 , wherein the code stored on the non-transitory computer-readable medium further causes processing circuitry to receive an output from the processing circuit configured for FEA simulations, the output comprising a flux linkage or the time-domain flux density of the at least one flux analysis coil as a function of time.

19 . The computer program product of claim 15 , wherein the code for causing processing circuitry to convert the calculated flux density function to the frequency-domain spectrum comprises code for causing processing circuitry to compute a discrete Fourier transform (DFT) of the time-domain flux density function.

20 . The computer program product of claim 15 , wherein the material core loss parameters comprise B-P curves.